Large hydraulic scaffolds are commonly used in the construction industry to allow workers to be properly positioned at the worksite to accomplish their task. Generally, the workers are constructing or working on a wall of a building or structure. As the work progresses, the hydraulic scaffold may be raised or lowered as required to re-position the workers and to acquire and off load additional materials. These hydraulic scaffolds provide a significant advantage over rigid scaffold, which is typically constructed in a fixed manner. Once constructed, the rigid scaffold requires that the workers climb up and down the skeleton of the scaffold to reach the work platforms. The skeleton of the platform must also be manually constructed and destructed to relocate the scaffold as the work progresses at the construction site.
A typical base scaffold unit includes a working platform section, hydraulic motors, lifting towers, etc. The length of the working platform of the hydraulic scaffold assembly may be expanded quite extensively by adding additional scaffold units to the base scaffold unit. An industrial-strength extendible-boom forklift is typically used to move the hydraulic scaffold and assemble the sections to form the scaffold assembly. To facilitate the lifting of these various scaffold sections, each scaffold unit includes pre-installed forklift tang receptacles on the edge and under the scaffold platform. These receptacles are positioned about the center of the length of the scaffold unit to accommodate the forklift tangs to facilitate the lifting and movement of that single unit such that the weight of the scaffold is roughly balanced.
When two sections of scaffold are coupled together to extend the working length of the platform, it is still desirable to lift the assembly from the center to balance the weight. However, the positioning of the tang receptacles on one section do not align with those on the other section to accommodate both forklift tangs when attempting to balance the load when lifting the assembly. However, the forklift must be positioned such that the load is balanced on each side of the forklift. Unfortunately, the spacing between the receptacles on each end of the connected sections is wider than the spacing between the forklift tangs. While one forklift tang may be accommodated in a receptacle of one platform portion, the receptacle of the added platform portion is not positioned to allow the other forklift tang to be accommodated therein. As a result, at least one of the tangs of the forklift is not accommodated in a receptacle and the scaffold simply rests on this tang. In this limited controlled configuration, damage to the hydraulic scaffold assembly, the support structures of the scaffold and the forklift may result.
Additionally, even when a single scaffold unit is lifted by a forklift with both tangs properly in the receptacles, the depth of the working platform for a typical hydraulic scaffold is such that a significant torque arm is presented to the forklift. As will be discussed more fully below in relation to FIG. 6, this torque arm is created because the forklift is required to lift the hydraulic scaffold from the side of the working platform. Indeed, this lifting position is furthest from the center of mass of the scaffold when the base scaffold unit is lifted. This is because the hydraulic motors, towers, and lifting mechanism must be positioned adjacent to the building so that the weight of the workers and bricks do not present a significant torque on the lifting structure of the scaffold itself during use. Furthermore, the offset center of mass of the scaffold is a safety feature, because this configuration tends to cause the scaffold to tip towards the building, rather than away from the building. However, the amount of weight and torque presented to the forklift that is lifting the scaffold from the side opposite the center of mass can be significant. The significant torque presented to the forklift by the weight of the scaffold has been known to create stress and fatigue cracking of integral lifting components of the forklift.
Indeed, this torque loading on the forklift resulting from the positioning of the forklift receptacles of these hydraulic scaffolds is such that it is difficult if not impossible to lift a hydraulic scaffold assembly that includes multiple scaffold units. As a result, the scaffold assembly must be taken apart to allow the scaffold to be moved around or to the work site. This assembly and disassembly process wastes significant amounts of time and money.
Not only is the need to assemble and disassembly the scaffold wasteful of time and money, but it is difficult as well. That is, adding and removing additional platform units to a hydraulic scaffold assembly is not aided by the positioning of the tang receptacles. This is because the positioning of the receptacles requires the forklift to be positioned transverse to the direction of movement necessary to add the additional platform unit to the assembly. Specifically, the receptacles require that the forklift be positioned perpendicular to the length of the scaffold unit. However, the scaffold unit must be moved in a direction along its length to be brought into conjunction with another unit. Since a typical forklift cannot move sidewise (perpendicular to the direction that it is facing), it is of little use in constructing the scaffold assembly.
However, since these units are quite heavy, it is most desirable to use the forklift to maneuver these units to aid in their assembly. Currently, in an attempt to use the lifting power of the forklift when assembly multiple units, chains or straps are used. Specifically, the forklift is positioned in-line with the length of the scaffold unit to be moved and chains or straps coupled to the scaffold unit are picked up by the tangs of the forklift. The forklift is then driven forward to bring the scaffold unit into conjunction with another unit. Unfortunately, since neither chains nor straps provide a rigid connection with the platform, the scaffold unit may swing and sway. This severely limits the forklift operator's control over movement and positioning of the additional scaffold unit. This lack of control over the scaffold unit requires additional workers to steady the scaffold unit while it is being lifted and moved into position and to assist in the assembly of the scaffold. Also, if the chains and straps are improperly attached to the platform, structural members of the platform may become damaged. Furthermore, the size of chains required to lift the scaffold are themselves heavy, inconvenient and expensive.
Therefore, there exists a need in the art for a mechanism that facilitates the lifting, movement, assembly, and disassembly of scaffold units that overcomes the above described and other problems existing in the art.